Picture printing plates and allied elements, and method and steps for making the same



March 3, 1936. G. E. LOSIER 2,032,541

A PICTURE PRIN ING PLATES AND ALLIED ELEMENTS,

AND METHOD AND STEPS FOR MAKING THE SAME Filed Sept. 5, 1934 5Sheets-Sheet l I 20 /7 /8 AVzo 4? v. m a A ,4 6 w m VAVNAvM A March 3,1936. o s I 2,032,541-

PICTURE PRINTING PLATES AND ALLIED ELEMENTS, AND METHOD AND STEPS FORMAKING THE SAME Filed Sept. 5, 1954 3 Sheets-Sheet 2 EE'DREE E, LEE/ERINVENTOR HIS ATTORNEY March 3, 1936. os 2,032,541

PICTURE PRINTING PLATEs AND ALLIED ELEMENTS,

AND METHOD AND STEPS FOR MAKING THE SAME Filed Sept. 5, 1934 3Sheets-Sheet 3 E'suRssE. LEE/ER INVENTOR HIS ATTORNEY Patented Mar. 3,1936 UNITED STATES PATENT- OFFICE PICTURE PRINTING PLATES AND,

ELEMENTS,

AND METHOD AND STEPS FOR MAKING THE SAME Orange, N. J.

Application September 5, 1934, Serial No. 742,715

12 Claims.

The present invention relates generally to machine etched cameo reliefprinting plates of the screen effect type and allied elements such asmonotypes and matrices, and such as wax engravings for makingelectrotypes all of the screen effect type; and the present inventionrelates more particularly to toolcut cameo relief printing plates andallied elements (in which the cameo reliefs have sloping sides like thesides of four sided pyramids or frustrums of four sided pyramids, but inwhich plates or elements said slop ing sides of adjacent cameo reliefsintersect each other at pyramidal corners) in the form of a multiplicityof substantially pyramidal or frustopyramidal shaped cameos adjacentones of which intersect each other at their sloping edges and thepresent invention relates to the method of cutting the same.

Heretofore automatically tool-cut cameo-relief printing plates have beenmade which were not of the screen grid type although they were attemptswhich were approximations thereof. However, most of the attempts in thisdirection are inoperative or impractical because of the comparativecumberscmeness of the apparatus and the attendant inherent inertiathereof or becausethey do not produce pure whites or even a practicalappearance of clear whites. Among these are the line half-tones of Bain(U. S. Patent #288,395) and Amstut-z (U. S. Patent #1,019,404); the linehalf-tone of Ainstutz made by mechanically scanning or tracing in atransverse direction over a previously made line half-tone plate (U. S.Patent #577,373); the line half-tone of Amstutz (U. S. Patent #569,595)made on a plate which had previously been transversely cut by grooves ofuniform depth and width; the rotating drill method of said Amstutz (U.S. Patent #569,595) or Howey (U. S. Patent #1,91 l,258) by which ovalholes are made to define cameo printing surfaces; and the known methodof photo-electrically scanning a picture and cutting a plate therefromtwice, the second time in a direction transverse to the first. But bynone of these methods is the screen effect produced. That is they failedto make a plate whichwould print a picture that can be viewed withcomfort or without the viewer being conscious of mechanical arrangementof the inked portions of the picture. The screen effect picture asphoto-chemically produced has been considered as being the best form orarrangement of small increments of ink to effect a picture which iscomfortable to the eye to see, and this is because the increments are soarranged that they blend by an optical illusion into the smooth andcontinuous gradations of shadings such as is presented by a photograph"An object of the present invention is to produce a cameo-reliefhalf-tone printing plate which gives the screen effect given by thephoto-chemical process and in which the several cameo-reliefs are notundercut as they are by the acid process but are tapering from theprinting surface thereof toward the bottoms of the surrounding groovesor cuts so that they are in the forms of frustums of pyramids. By virtueof this form the strength of the printing plate is increased and greaterpressure can be used thereon and a great or number of good pictures canbe printed therewith. Also matts and electro-plates can be made fromthese plates and wax engravings without the disadvantage of the snaggingmushroomed tops of the cameo-reliefs.

Another object of the present invention is to provide a, method ofmechanically cutting screen effect cameo-relief printing plates in whichthe printing surfaces of the several cameo-reliefs are substantiallysquare in shape; in which the substantially square cameo printingsurfaces are substantially aligned diagonally in both directions;

and,'in the medium shade portions, adjacent cameo printing surfacestouch or nearly touch at their corners; and in the dark or below mediumshade portions the printing surface is continuous, with substantiallysquare spaced-apart interruptions interspersed therethrough of varioussizes to give various dark shades.

Another object is to provide a single operation mechanical method ofcutting a cameo relief screen effect printing plate with a V-shaped toolwhereby successive parallel rows of substantially square shaped cuts aremade in the direction of the diagonals of said squares, whereby saidsquare shaped cuts are spaced apart in their rows and their rows arespaced apart at the dark printing portions of the plate; said squareshaped cuts touch or substantially touch at their corners at the mediumshade printing portions of said plate, and said square shaped cuts runtogether along both diagonals in the portions of the plate which printlighter than medium shade and where there is no printing surface left.

In the drawings forming a part of this specification there are viewsshowing cameo reliefs of various sizes for the purpose of illustratingthe relation of such cameo reliefs to each other as they might occur ina printing plate of the present invention, and also to illustrate thetool used for cutting said printing plate, together with a pictureprinted with a plate made according to the present invention. In thedrawings, showing illustrative embodiments of the present invention;

Figures 1, 2 and 3 are side, back and front views, respectively,illustrating the cutting end of a tool used for making the plate of theinvention, the drawings in these figures being enlarged about six timesfor purposes of illustration;

Figure 4 is a plan view of a tone cut plate ha ing frusto pyramidalcameo reliefs of various sizes;

Figures 5, 6, '7 and 8 are sectional views taken along the lines 55,6-6, 1-1 and 83, respectively, of Figure 4, looking in the directions ofthe arrows;

Figure 9 is a plan view, in part cut away, of a portion of uniform toneof a partly cut printing plate;

Figure 10 is a perspective view corresponding to Figures 4 to 8, and istaken looking diagonally from the lower right hand corner of Figure 4;and

Figure 11 is a print made from an actual plate of the present invention,having sixty dots to the inch.

Referring now to Figures 1, 2 and 3 of the drawings, the cutting tool I0has a V-shaped cutting end ll whose cutting edges l2, l2 are at an angle(A) of about one hundred and eight degrees to each other or each at anangle (B) of about fifty-four degrees from a normal to the plane of thesurface to be out (see Fig. 2). The face l3 hasa drag at an angle (C) ofabout six degrees from a normal to the surface to be out (see Fig, 1),and the back is ground back from both said cutting edges l2, l2 to aline having a clearance at an angle (D) of about forty-five degrees fromthe plane of the surface to be cut. The arrow X of Figure 1 indicatesthe direction of relative movement of said V-shaped tool Ill over orunder the surface of a plate being cut, as indicated also by the arrowsX of Figures 4, 7, 9 and 10.

In the use of said V-shaped cutting tool III in cutting a cameo reliefprinting plate, such as illustrated in Figures 4 to 11 for example,successive parallel cutting strokes are made at a predeterminedlongitudinal rate of movement across the plate and the cuts are made ata predetermined distance from each other, uniform throughout the plate.While the tool is cutting, it is caused to move up and down at a certainrate with respect to the rate of relative longitudinal movement thereofwith respect to the plate, said rate ofup and down movement being of apredetermined value for all tones of shading, but changing slightly atchanges from one tone to another, the limit of each downward movementbeing determined according to the light or shade of a picture to bereproduced, as done for example by the apparatus and according to themethods set forth in my copending applications Serial No. 645,384, filedDecember 2, 1932 and Serial No. 647,884, filed December 19, 1932, of theformer of which the present application is a continuation in part. Andsuch said rate of up and down movement of said V-shaped tool Iii ispredetermined so that the distance between the lower limits ofsuccessive downward movements is substantially equal to the saidpredetermined distance between successive parallel cutting strokes.

Referring now more particularly to Figures 4 to 10 in the tool cutprinting plate IS, a number of tetrahedral depressions. Iii, i3 extenddownwardly from the printing surface l'l thereof. In the lower left handcorner of Figure 4 and in the left hand corner of Figure 10 saiddepressions I8, I 3 are comparatively small and the surface cut away ismuch smaller than the surface left for printing but going in thediagonal direction that is, upwardly toward the upper right hand cornerof Figure 4 and transversely in Figure 10, said depressions l6, l6increase in size so that at about the center of the plate IS the surfaceleft for printing is about equal to that which was taken away where thedepressions were cut. In the upper right hand comer of Figure 4 and inthe right hand corner of Figure 10 the printing surface is smaller thanthe surface taken away; and here the said depressions l6, l6 run intogether around a number of four sided pyramidal frustums l8, l8 whoseseveral square top printing surfaces l1, II are parts of the originalsurface l'l. Near the center of said printing surface II, where thesurface left is equal or about equal to that cut away, said squaresurfaces i1, i1 touch or nearly touch at their corners.

In making each cut in the direction indicated by said arrows X the pointof said V-shaped tool I0 defines a line 20 which is at the bottom of theout (see particularly Figures 4, 7, 9 and 10). In those portions of saidplate II where the tone of the reproduced picture is medium or darkerthan medium, said line 20 will be interrupted because the point of saidV-shaped tool l0 comes up to or higher than the surface of the plate(see Figure 7); and in those portions of the plate where the tone islighter than medium, said line 20 is continuous; but in every case saidline 20 rises and falls as a result of the rise and fall of said tool l0and as said V-sha-ped tool 10 changes from a fall to a rise in itscutting movement, said cutting edges l2, l2 leaves transverse lines 2|,2| (see particularly Fig. 8) which, in effect, are at the bottoms ofslanting V-shaped troughs, in accordance with the slopes of said cuttingedges whose crests are the lines 23, 23 and lie beneath I the plane ofthe original surface of said plate 15 (see Figures 4, '7, 9 and 10),said lines 23, 23 being formed successively in pairs, the first onesloping downwardly and the second one continuing from the first andsloping upwardly; and, in the same portions of plate l5, transverseridges whose crests are the lines 24, 24 are defined where the toolchanges the direction of its movement from the upstroke to thedownstroke, said lines 24, 24 are formed simultaneously in pairs by thetwo cutting edges l2, l2 of said tool II as the latter changes from anupward to a downward stroke.

Referring particularly to Figures 4 and 10 and referring again to thoseportions of said plate l5 where the tone is lighter than medium, anumber of separate surfaces l1, ll of the original sur face H of saidplate I 5 are isolated after the surrounding portions of the plate havebeen cut away at the parts where the point of said tool Ill remainsentirely below the surface, and each of said surfaces i1, i1 is the topsurface of one of said four sided pyramidal frustums I8, I 3 whosesloping sides are defined laterally by two each of said lines 23, 23 and24, 24. Each of said frus-- edges against another like frustum andlaterally at a V shape point of each of its sloping sides against thebase of each of four other like frustums (or parts of frustums in thoselight portions of the plate which are next adjacent to medium toneparts) and is supported thereby when pressure is applied when a print ormat is made and such support is substantially as strong for a surface Hwhich is small as for a large. one because the lateral surfaces of eachof said frustums l8, I8 slope upwardly from a comparatively wide base tothe top and do not undercut the top surface I1.

It is to be noted that, in a printing plate in which the cameo reliefs(which are frustums l8, l8) are spaced apart at the same distance bothlongitudinally and transversely, the angle between a given pair of saidlines 2|, 2| will be the same as the angle (A) between said cuttingedges l2, I! of said tool H), as will be also the angle between a givenpair of said lines 24, 24. That is, the several angles between givenpairs of said lines 20, 20; 2|, 2|; 23, 23 and 24, will all be the sameand equal to said angle A. The angle between said pairs of lines 2|, 2|and 24, 24 is determined of course by said angle A, but the anglebetween said pairs of lines 20, 20 and 23, 23 to be made equal to angleA is predetermined by the relation between the speed of said tool I0across said plate l5 and the speed of said tool I 0 in its downward andupward movement into and out of said plate l5. In order to get thespacing of the cameo surfaces the same in both the transverse andlongitudinal direction, this predetermined relation must be such thatthe ratio of the rate of speed of said tool I0 across said plate l5 tothe rate of speed of said tool l0 into and out of said plate I5 issubstantially equal to the tangent of half the angle A, that is equal tothe tangent of said angle B, with the additional provision that thedistance between successive cutting strokes of said tool l0 across saidplate l5 must be substantially equal to the distance between the bot tompoints of two successive downward movements of said tool Ill for aportion of even shading, or substantially equal to the average distancebetween the bottom points of successive downward movements'of said toolID.

The above description is for a plate made by cutting in one directiononly and with a substantially V-shaped tool under optimum operatingconditions, but several variations therefrom may occur without departingfrom the general physical relations and details above set forth andwithout departing from the description of the plate of the presentinvention as set forth in the appended claims. These variations whenthey occur are slight, some of them being compensating one to another,and none of them detracts effectively from the advantages above setforth for the products of the present invention. Some of thesevariations and the causes thereof may be as follows. The hardness orsoftness of the material being cut might effect the characteristics ofthe cuts made, whether type metal, zinc,

copper, etc., for printing or for making matrices of wax or other softmaterial for making electrotypes. In some substances or materials thetool might come up out of a out faster than it entered, but, due to thesmall size of the individual cuts made, the variation when printed wouldnot be noticeable to the eye. In any case the cutting apparatus could beadjusted to operate with substantially optimum characteristics onmaterials of various characteristics or decutting strokes.

grees of hardness. When the rate of movement of the tool down (or up)varies, the sides of the pyramidal 'frustum are not plane but slightlyconcave and the corresponding side or edges of the resulting cameosurfaces are curved lines instead of being straight. At the point orline where the size of the cameo reliefs changes (corresponding to thepoint or line where there is a change in tone in the picture) theprinting surface of the cameo relief is not exactly square and thedistance between centers in the direction of the parallel cuts is notexactly the same as at a part where the size of the cameo reliefs arethe same (where the tone is uniform), and over a given. I

unit of distance at any part the number of cameo reliefs is uniform. Butin any case these differ.- ences can be made so small as to benegligible and in no case is there any undercutting.

In cutting the plate of the present invention with said tool In,illustrated in Figures 1, 2 and 3, to get the best results the median ofsaid angle A should be perpendicular or in a plane perpendicular to theplaneof said plate l5 and said face l3 should be directly forward withrespect to its movement relative to said plate I5inthe parallel If thepoint of said cutting end !'I of tool In does not come to a good pointsaid depression l6, l6 in shades up'to medium shades will not be squarebut will be six sided or will have its forward and rear corners rounded,and in place of said lines 20, 20 there will be two lines closely spacedat the distance equal to the width at the blunted end of the point orthere will be a curved trough.

The reproduction shown in Figure 11 of the drawings is a print from anactual printing plate of the present invention and graphically shows theresults of machine etchings of various width and depth in the sameplate. For example, the derby shown at the left hand side of the pictureis very dark as compared with most of the other parts of the picture andhere the plate is continuous with small indentations therein and someparts are solid black particularly the part of the derby next to thehand holding it. Just adjacent the right shoulder of the figure, ashadow on the wall is shown in medium tone with the printed dots almostexactly square in shape. The rail on which the figure is leaning isshown in good contrast between a medium tone on the side surface thereofand a slightly lighter shade on the top surface. The vertical postsupporting the rail and also the handkerchief in the figures pocket showhigh lights in pure white.

The plate from which the sixty screen reprohundred reciprocations persecond and with an average rate of over four hundred reciprocations persecond, the variations being due to the harmonic movement of the cuttingtable or bed on which the plate rode while being cut. With a cuttingtable moving at a uniform rate of speed the higher rate of cutting couldbe maintained throughout. that is over six hundred reciprocations of thecutting tool per second. Forcutting a finer screen picture the rate ofmovement of the cutting table could be decreased but preferably it couldand would be increased to double the speed used for the sixty screencutting. The power used on the cutting head could be increased, but thedepth of the cut would not need to be so much as in the case of thecoarser screen.

What I claim as new and desire to protect by Letters Patent is:

l. A screen effect reproduction adapted for use in the printing artscomprising a multiplicity of four-sided projections, and having aplurality of depressions which are substantially square in plan andwhose surfaces are substantially tetrahedral in form.

2. A screen effect reproduction adapted for use in the printing artscomprising a multiplicity of four-sided projections which aresubstantially frusto-pyramidal in shape, and having a plurality ofdepressions which are substantially square in plan and whose surfacesare substantially tetrahedral in form.

3. A screen effect reproduction adapted for use in the printing artscomprising a multiplicity of four-sided projections of various sizes,which said projections are substantially frusto-pyramidal in shape-andthe lateral surfaces of which at their bases come to substantial pointson their respective medians.

4. A tool cut screen effect printing plate having formed in the printingsurface thereof a plurality of holes whose surfaces define substantiallythe lateral surfaces of tetrahedral angles.

5. A screen effect printing plate having cut in the printing surfacethereof a plurality of depressions which are substantially square inplan and whose surfaces are substantially tetrahedral in form.

6. A machine 'etched printing plate of the screen effect type forreproducing a chiaroscuro picture on which plate the light portionscomprise a multiplicity of four sided printing surfaces, the darkportions comprise substantially continuous printing surfacesinterspersed by four sided depressions, and the medium shade portionscomprise a multiplicity of four sided printing surfaces touching attheir corners and interspersed with four sided depressions definingcutaway areas substantially equal to the adjacent printing surfaces, andcorresponding variations where portions of different shade adJoin eachother.

'7. A machine etched printing plate of the screen effect type having amultiplicity of printing surfaces defined by a multiplicity ofsubstantially square, cut depressions having substantially pyramidalsurfaces, said printing surfaces being substantially square. v

8. The method of forming a screen effect reproduction of pictures,images and the like, having a plurality of holes that are substantiallysquare in plan and whose surfaces are substantially tetrahedral inshape, comprising beginning at a comer and ending at a diagonal cornerand making each hole of a depth, length and width proportional to thedegree of shading desired in the corresponding part of the picture orimage to be reproduced. l

9. The method of forming a screen'effect reproduction of pictures,images and the like, having a plurality of holes thatare substantiallysquare in plan and whose surfaces are substantially tetrahedral inshape, comprising beginning at a corner and .ending at a diagonal cornerand making each hole of a depth, length and width proportional to thedegree of shading desired in the corresponding part of the picture orimage to be reproduced, said method being further characterized bythefacts that at those portions of the plate which correspond to shadeslighter than medium the said holes are made continuously inlongitudinally connecting relation and are made of such maximum. widthsthat they run into each other laterally.

10. The method of making a cameo relief printing plate which comprisesmaking parallel series of cuts with a V-shaped pointed tool, the severalcuts of each series being made to a depth and for a longitudinaldistance proportionate to the degree of light or shade of .a picture tobe produced, in such a manner that at the part of the plate for printingwhite or a light shade the cuts of adiacent series overlap and one sideof said V-shaped tool passes through portions already cut in theadjacent series by the opposite side of the tool and forms cuts thereatsloping in an incline reversed to the slope cut by said opposite side ofthe tool in the previous series.

11. The method of cutting a screen effect en- 4 graving with a cuttingtool which comprises moving said tool across a surface to be out whilereciprocating said tool substantially p p ndicularly to said surface insuccessive cutting engagements at a rate of more than two hundredreciprocations per second while varying the distance of eachreciprocation into said surface in a predetermined manner.

12. The method of making a screen effect cameo relief engraving by rowsof parallel series of cuts with a symmetrical V-shaped tool having agiven angle at the V whereby the cameo reliefs are spaced apartsubstantially equidistant both in said given direction and in thedirection transverse thereto which comprises moving said symmetricalV-shaped tool in cutting relation over a surface to be cut in asuccession of parallel passes half the angle at said V. and making saidparallel passes at a distance apart substantially equal to the distancebetween the bottom points of two successive downward movements.

GEORGE E. LOSIER.

